This application claims the priority of Korean Patent Application No. 2002-36311, filed on Jun. 27, 2002, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to electronic maps provided through a network, and more particularly, to an apparatus and method for displaying a detailed map of a selected area of a displayed map.
2. Description of the Related Art
A related art map provider service in an Internet-based web scheme provides a detailed map of a selected area of a map displayed on a map display device, such as a display device of a computer or a personal digital assistant (PDA). When an area desired to be displayed through a detailed map is requested using an input means, such as a mouse in the case of a computer or a stylus pen in the case of a PDA, a map provider server transmits data of a low scale map of the desired area to the user. Thus, an enlarged and detailed map of the desired area is displayed.
The related art map provider server stores map data using a layer structure. If the map provider server stores data on maps drawn to various scales for an area, each layer denotes data on a map drawn to a predetermined scale. When a map drawn to a high scale is viewed at a low scale, the geographical information displayed on a screen becomes very detailed, and the map can be hardly distinguished. To solve this related art problem, various map data to different scales are made to constitute such a layer structure. Accordingly, a map drawn to a high scale shows a large area, but does not provide detailed geographical information, and a map drawn to a low scale provides geographic information, but only for a small area.
FIG. 1 shows an example of a detailed map displayed according to a related art technique. A user requests a detailed map of a dotted rectangular area on a map on the left, which is drawn to a scale of 1:9000. The map on the right corresponds to the detailed map for the dotted area on the map on the left, and is drawn to a scale of 1:3000.
As shown in FIG. 1, in a related art map provider service through a network, if a detailed map of a certain area is requested, a map to a low scale of the area is displayed over the entire screen while the previous high scale map disappears. Accordingly, only a small area is shown on the entire screen, making it hard to discover where the displayed small area is located with respect to the entire (i.e., larger) area. To ascertain the location of a particular area with respect to the entire area, some users might require the original map and the detailed map to be visualized several times, which is not provided in the related art.